Science Topics – 156
Synchronized movements to periodic events, such as dancing to music or clapping hands, are common in daily life. Such movements require multiple neural processes, including adjustment of movement timing, detection of temporal error, and maintenance of internal rhythms. Despite the involvement of the cerebellum, the underlying mechanism remains unclear.
In this study, we examined single neuron activity in the cerebellar dentate nucleus while monkeys performing synchronized saccades to periodically alternating visual stimuli. Three types of neurons carried information that seemed essential for synchronized movements. First group exhibited preparatory activity with a strong directional preference, which closely correlated with the timing of the next saccade. Second group showed preparatory activity for saccades in both opposite directions and represented an internal model of rhythmic structure rather than a specific motor command. Third group showed a transient activity immediately after saccades, which correlated with the temporal error of synchronized saccades.
These results suggest that the lateral cerebellum contains multiple functional modules for the maintenance of internal rhythms, predictive motor control, and error detection during synchronized saccades. Each module may work in parallel to synchronize movements by sending information to different areas in the cerebral cortex.
Neural signals regulating motor synchronization in the primate deep cerebellar nuclei.
Okada, KI. Takeya, R. & Tanaka, M.
Nature Communications 13, https://doi.org/10.1038/s41467-022-30246-2, 2022.
＜Figure Legends＞ A. Saccade targets appeared alternately at regular intervals in the left and right landmarks. Monkeys were rewarded for synchronized saccades. Synchronized movements require multiple neural processes, including prediction of target timing, precise motor control, and detection of temporal error for updating the prediction. B. Neuronal activity of cerebellum were classified into three categories by cluster analysis.
Department of Physiology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan